Fibrous material handling apparatus



Noin'S, 1957 H. KOCH ET AL FIBROUS MATERIAL- HANDLING APPARATUS Filed March 21. 1986 In venfors: jfans jzoc/z Carl ,Burc/zard flitorrley.

United States Patent FIBROUS MATERIAL HANDLING APPARATUS Hans Koch, Hamburg-Rahlstedt, and Carl Burchard,

Hamhurg-Bergedorf, Germany, assignors to Kurt Korber & Co., K. G., Hamburg-Bergedorl", Germany Application March 21, 1956, Serial No. 572,907

Claims priority, application Germany March 21, 1956 2 Claims. (Cl. 30259) This invention relates generally to fibrous material handling apparatus and more particularly to an apparatus for transporting and discharging cut tobacco.

In tobacco processing operations it is customary to transport the cut tobacco through a pneumatic tube system from one processing station to the next. In cigarette manufacturing such a tube system may transport cut or shredded tobacco to a discharge device over the spreader apparatus of a cigarette machine. Such a discharge device receives the tobacco from the pneumatic tubes and periodically discharges it onto said spreader.

In prior art arrangements the cut or shredded tobacco was separated in the air stream in the discharge device by means of sieve like walls which were perpendicularly disposed within the device, with respect to the discharge air stream. The discharge of the shredded tobacco onto the spreader was accomplished through a door in the discharge device over the spreader. Sometimes cell wheel dischargers or similar deidces were employed in place of the discharge door.

These devices discharged at timed intervals, controlled and operated by suitable timing devices. In most cases the conveying air flow was interrupted in the discharge device. Frequently this was accomplished by means of an electric controlled switch-over device disposed in the discharge air conduit and operated by side-air. When the air flow was interrupted the discharge door, normally held closed by atmospheric pressure due to the lower suction pressure in the chamber, opened discharging the tobacco from the device.

Such an arrangement requires substantial overhead clearance due to its height which is undesirable. Further the disposition of the screen or sieve was such as to result in frequent clogging of same, requiring frequent cleaning. This meant frequent shutdowns which is not profitable. The clogging of the sieves is due principally for the reason that the tobacco is fed vertically against the sieve and the tobacco therefore is directly pressed into the apertures of the sieve.

In another prior art arrangement the tobacco is discharged from a suction pressure air stream by means of two chambers respectively provided with flaps in the bottom thereof and connected with each other by an air conduit. Control means were provided in said connecting conduit to alternately connect the lower chamber with ambient pressure or with the suction pressure in the upper chamber. The opening and closing of the flaps being controlled by pressure differences in the chamber produced by the above mentioned control means.

Here again the height of the device is unsatisfactory. The separating screen is parallel to the conveying air conduit, but perpendicular to the discharge air conduit which leads upwardly. in practice this screen also quickly clogged requiring frequent shutdowns.

Accordingly, this invention has for one of its objects a fibrous material handling and discharge device, which is relatively free of clogging and thus need not be shut down for frequent cleaning.

Another object of this invention is to provide a tobacco handling and discharge device which is relatively compact in comparison with prior art devices.

More specifically it is an object of this invention to provide a tobacco handling and discharge device involving a separating screen between the inlet and discharge air conduits wherein the screen is disposed substantially parallel with respect to the air flow, to substantially minimize the tendency of the tobacco to lodge and stick to the screen. This arrangement overcomes the tendency of the screens to become clogged, because the tobacco stream passes horizontally over the screens.

The foregoing statements are merely illustrative of the various aims and objects of this invention. Other objects and advantages will become apparent from a study of the following specification when considered in conjunction with the accompanying drawings, in which:

Fig. 1 is a side elevational view of a tobacco handling and discharge device embodying the principles of this invention, and

Fig. 2 is a sectional view taken along the line 11-11 of Fig. 1.

The invention accomplishes the functions set forth in the objects aforesaid in the provision of a discharge chamber having inlet and discharge conduits in opposite ends, the discharge conduit being disposed above the inlet and the chamber being divided into two communicating compartments by means of a screen separating the inlet and discharge conduits and arranged substantially horizontally therewith and substantially parallel to the air path therethrough. in this arrangement provision is made for periodically interrupting the air stream in any suitable conventional manner, to permit discharging of the fibrous material or tobacco. Thus the tobacco which has collected on the bottom face of the screen falls downwardly through the discharge opening.

In the drawing the discharge air conduit 1 which may be connected to a suitable suction blower (not shown) draws air from the discharge chamber 2 which is divided into upper and lower chambers 3 and 4 respectively by means of a screen or perforated plate 5. This screen 5 is mounted in a suitable frame 5a provided with suitable handles 6 and 6, and which is slidably mounted in guides 51) in the discharge device so that it may be pushed in and withdrawn from the chamber. The inlet pipe or tube which conveys the tobacco to the discharge device is designated 7. It will be noted that this tube 7 lies below the level of the discharge tube or conduit 1 in the opposite end of the device and that the screen 5 separates the two conduits, forming the chambers 3 and 4.

As will be seen by reference to Fig. 2 the bottom of the discharge device, that is chamber 4, is of triangular shape. One side 8 is hinged as a door at 9 to a fixed wall of the chamber 4 and arranged so that its lower end swings outwardly, as indicated in dotted outline, to open the bottom of the discharge chamber 4 to discharge the tobacco therefrom. An electric contact device 11, which may be a pressure sensitive device actuated by tobacco pressure, is adjusted to operate when the lower chamber 4 is substantially full. This switch is located in the fixed wall of the lower chamber opposite the door 8.

Suction air pressure moves the tobacco from a loading station (not shown) through inlet conduit 7 to the lower chamber 4. The air moves from left to right of the discharge device, as seen in Fig. 1, from the inlet conduit 7 and out the discharge conduit 1, as indicated by arrows. The air stream crosses the screen 5 at a very shallow or acute angle, in fact the air stream substantially parallels the screen in its travel from the inlet to the discharge conduit. The tobacco enters the lower chamber at sufficient velocity that it is carried by its momentum and the air stream to the right end of the lower chamber, as seen in Fig. 1, filling the lower chamber 4 from right to left as it falls from the air stream. Since the air stream flows substantially parallel to the screen its vertical component of velocity in the lower chamber 4 is substantially zero and consequently there is very little tendency to accelerate the tobacco shreds toward the lower side of the screen. Consequently the tobacco fallout from the moving air stream into the lower chamber is very efiicient, practically none of it moving upwardly against the screen to impede the air flow therethrough.

As the lower chamber fills towards the left, the tobacco weight on the pressure switch 11 actuates the switch. This switch may form part of an electric circuit (not shown) which operates a switch-over device or air baffle in the discharge conduit 1 which closes the discharge device from the suction pressure and opens the conduit 1 to the atmosphere. The resulting rise in pressure in the discharge device coupled with the weight of the tobacco in the lower chamber 4 on the door 8 forces the door to its open position which allows the tobacco to discharge through the now open bottom of the chamber. Since the air flow has been interrupted such strands of tobacco which might have lodged against the lower side of the screen, now fall free through the bottom of the chamber 4, due to the lack of air flow across the screen.

Although but one embodiment of this invention has been illustrated and described it will be appreciated by those skilled in the art that numerous changes in the apparatus, both in its details and in the organization of such details may be made, without departing from the spirit and scope of the present invention. Accordingly it is intended that the foregoing disclosure shall be considered only as illustrative of the principles of this invention and not construed in a limiting sense.

We claim as our invention:

1. A device for handling pneumatically transported shredded fibrous material comprising an elongated casing forming a main chamber having a pneumatic inlet conduit at one end thereof and a pneumatic discharge conduit at the opposite end thereof, said conduits communicating through opposite ends of said elongated casing and said discharge conduit being disposed in a horizontal plane above said inlet conduit, a screen extending horizontally in said casing arranged in a plane above said inlet conduit and below said outlet conduit, means slidably mounting said screen in said elongated casing, said screen being removably supported in said casing to permit the same to be removed for the purpose of cleaning, air flow between said inlet and discharge conduits being such that the flow path crosses said screen at an acute angle with a relatively small vertical component of velocity, said air flow having a component relatively longitudinally of said main chamber sufficient to carry the shredded material to the end of the casing adjacent said discharge conduit and filling said casing from said opposite end back to the end adjacent said inlet conduit, a pressure switch in said casing mounted at one end thereof adjacent said inlet conduit adapted to interrupt the flow through said chamber, and a door in the bottom of said lower chamber for discharging the shredded material periodically when the air flow through said casing is interrupted.

2. A device for handling pneumatically transported shredded fibrous material comprising an elongated casing having a pneumatic inlet conduit and a pneumatic discharge conduit at the ends thereof, said discharge conduit being arranged above said inlet conduit with the axes of said conduits oflset vertically, a pair of slide guides in said casing secured to the end walls thereof with one guide arranged above said inlet conduit and the other guide arranged below said discharge conduit, :1 screen slidably mounted in said guides and adapted to be removed through an opening in the side wall of said casing, said screen being arranged horizontally and longitudinally of said casing to divide said casing into upper and lower portions, said inlet and discharge conduits being arranged such that the flow path crossing said screen is at an acute angle thereto with a relatively small vertical velocity component, said air flow having a component longitudinally of said casing sufficient to carry the shredded material to the end thereof opposite said inlet conduit to fill said lower chamber from said opposite end back to the end adjacent said inlet conduit, a pressure switch in the bottom of said lower chamber at one end thereof adjacent said inlet conduit adapted to interrupt air flow in said chamber, and a door hinged to the side wall of said casing and extending the entire length thereof to periodically discharge the shredded material from the lower chamber when the air flow in said casing is interrupted.

References Cited in the file of this patent UNITED STATES PATENTS 2,104,881 McLemore Jan. 11, 1938 2,153,984 Leicht Apr. 11. 1939 2,342,872 Le Fevre Feb. 29, 1944 

